SECOND NITROGEN FIXATION SYSTEM DISCOVERED 
     
    
   
   
    
     Dr. Richard w. Millen, a biochemist with Agriculture Canada, and Drs. 
     
     Robert L. Robson and Robert R. Eady, of the University of Sussex in England, 
     
     have found a second biochemical process for the fixation of nitrogen. This 
     
     process uses the metal vanadium to form the nitrogenase enzyme which allows 
     
    

    
     certain bacteria living in root nodules 
     
    

    
     to change air or water borne nitrogen to 
     
     nitrogen fixing nodules a form capable of being absorbed by the 
     
     host plants and other plants. As this 
     
     process is critical to the use of clovers 
     
     and other nitrogen fixing plants to 
     
     improve soils by rotating crops, the 
     
     finding is quite important. 
     
    

    
     In addition to the discovery of the process itself, the researchers have 
     
     shown that this process is controlled by a separate set of genes from that used 
     
     by the nitrogen fixing system of molybdenum-nitrogenase which has been know for 
     
     some time. The researchers utilized the bacterium Azobacterer in their original 
     
     work and Dr. Miller now wishes to determine if this system is also found in the 
     
     bacteria Rhizobium which are important in nitrogen fixation in many Canadian 
     
     crops. - 
     
    

    
     (Excerpted from an article by Lorraine Brown of Canadian Science News 
     
     titled "Soil Bacteria Have a Second System for Fixing Nitrogen" from the 
     
     Halifax Field Naturalists' Newsletter # 57.) 
     
    
   
   
    
         
     
    
   
   
    
     CRONS 0N ICE by Margaret E. Mallett 
     
    
   
   
    
     This spring, on April 5th, just before sunset I drove around Victoria Park 
     
     to see how the ice break-up in Charlottetown Harbour was progressing. 0n the 
     
     eastern side, there was open water out to the Hillsborough Bay. The break-up 
     
     there was promoted by the passage of several tankers in to the port at the end 
     
     of March and the first of April. However, the estuaries of the West and North 
     
     Rivers and the area about the park were still icebound. (by April 11 the ice 
     
     was all gone). 
     
    

    
     Continuing along to the town side of Fort Edward, my expedition became a 
     
     crow and gull watching session. 
     
    

    
     When I stopped at Fort Edward, a woman was out of her car, scattering bits 
     
     of bread on the ground. Not many birds came until she drove away. Then there 
     
     were customers such as several adult Herring Gulls, a first year Herring Gull, 
     
     a Ring-billed Gull, an Iceland Gull, some crows and one starling. 
     
    

    
     Across the ice, on a point of ice extending out from the Queen Charlotte 
     
     Armories, there were at least 100 crows. A little later, on the ice between 
     
     Fort Edward and Beaconsfield, the number of crows grew to another hundred. 
     
    

    
     Shortly after sunset several flocks of gulls flew over, heading eastward 
     
     across the harbour. This did not trigger a mass exodus of crows as I half- 
     
     expected, so near roosting time. It was nearly dark when they began to depart 
     
     in small groups but not before about 30 of them had been up on the bank to pick 
     
     up the last crumbs of bread. As I drove away at dusk, three crows flew away 
     
     leaving three stragglers still on the ice. Somewhere, not far away, a number of 
     
     trees would be required to lodge some 200 crows for the night. - 
     
    

    
     Up to that time I did not understand the affinity between crows and ice, 
     
     except that the ice was a nice level place to stand and enjoy the sunshine, to 
     
     be relatively undisturbed by human beings, and to have a sip of water available 
     
     when required. 
     
    
   
   
    
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